**Core Concept**
Magnetic Resonance Imaging (MRI) in obstetric practice is used for evaluating fetal and placental anatomy, especially when ultrasound is inconclusive. **MRI** is particularly useful in assessing fetal development, detecting anomalies, and evaluating placental invasion. It does not use ionizing radiation, making it a safer choice for pregnant women.

**Why the Correct Answer is Right**
Since the correct answer is not provided, let's discuss a general concept. **Gadolinium**, a contrast agent, is typically avoided in pregnancy due to potential risks to the fetus. However, **MRI** itself is considered safe, especially after the first trimester. The choice of answering this question correctly depends on understanding what is false regarding **MRI** use in obstetrics.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, we cannot directly address its incorrectness. However, if it pertains to the safety of **MRI** in pregnancy, it would be incorrect if stating **MRI** is unsafe.
**Option B:** Similarly, without specifics, if option B suggests **MRI** is always necessary, it would be incorrect because **ultrasound** is the first-line imaging modality.
**Option C:** If option C claims **MRI** can be used without caution in the first trimester, it might be misleading because, although **MRI** is safer than CT scans, caution is still advised.
**Option D:** If option D states **MRI** is contraindicated in pregnancy, it would be incorrect as **MRI** can be used when benefits outweigh risks.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that while **MRI** is valuable in obstetrics, it should be used judiciously, especially in the first trimester, and **gadolinium**-based contrast agents are generally avoided due to potential fetal risks.

**Correct Answer:** Correct Answer: D. MRI is contraindicated in pregnancy.