**Question:** The completed family size may be estimated by

A. Average number of children born to a woman
B. Total number of children born to a woman
C. Total number of children born to a man
D. Total number of children born to a couple

**Core Concept:** The concept of completed family size refers to the total number of children that a couple or a woman has given birth to.

**Why the Correct Answer is Right:** The correct answer, D. Total number of children born to a couple, is based on the understanding that a couple forms the reproductive unit in terms of giving birth to children. The couple's completed family size is determined by combining the reproductive output of both partners.

**Why Each Wrong Option is Incorrect:**

A. Average number of children born to a woman (A) is misleading because it only considers the reproductive output of a single individual and does not account for the partner's contribution.

B. Total number of children born to a woman (B) is incorrect because it ignores the partner's reproductive output, leading to an incomplete estimation of the couple's completed family size.

C. Total number of children born to a man (C) is irrelevant because it focuses on the reproductive output of one individual, failing to consider the contribution from the partner.

**Clinical Pearl / High-Yield Fact:** Understanding the concept of completed family size is essential in epidemiological studies, demography, and public health research, as it provides insights into population dynamics, fertility, and family planning. Families with fewer children are more likely to utilize modern contraceptives, which can help reduce maternal and child mortality rates.

**Correct Answer:** D. Total number of children born to a couple

---

**Core Concept:** The completed family size is a crucial parameter in understanding demographic and epidemiological data, as well as in family planning policies and interventions.

**Why the Correct Answer is Right:** D. Total number of children born to a couple represents the combined reproductive output of both partners, making it the most accurate measure of the completed family size. In a couple, each individual contributes to the number of children born, and considering both partners ensures a comprehensive estimation of the family's reproductive potential.

**Why Each Wrong Option is Incorrect:**

A. Average number of children born to a woman (A) is flawed because it only considers the reproductive output of a single individual, ignoring the contribution of the partner, which is essential for accurate estimation of completed family size.

B. Total number of children born to a woman (B) is incorrect because it neglects the reproductive output of the partner, causing an incomplete estimation of the couple's completed family size.

C. Total number of children born to a man (C) is irrelevant because it focuses on the reproductive output of a single individual, failing to account for the contribution of the partner, which is crucial for accurate estimation of completed family size.