**Core Concept**
Oogenesis is the process of formation of a female gamete or ovum from the germ cells in the ovaries. It involves meiosis which is a two-part cell division process, reducing the chromosome number by half to form a haploid gamete. The meiotic process in females is unique due to its arrest at specific stages until ovulation.

**Why the Correct Answer is Right**
The correct answer is related to the unique characteristics of oogenesis. Primary oocytes indeed arrest in prophase of the first meiotic division, a stage known as diplotene arrest, until the female reaches reproductive maturity and the oocyte is about to be ovulated. This arrest is crucial for the prolonged maintenance of oocytes in a dormant state. Upon ovulation, the first meiotic division completes, and the first polar body is extruded, resulting in the formation of a secondary oocyte, which then arrests in metaphase of the second meiotic division until fertilization occurs.

**Why Each Wrong Option is Incorrect**
**Option B:** This is incorrect because primary oocytes arrest in prophase of the first meiotic division, not the second.
**Option C:** This is incorrect because the secondary oocyte arrests in metaphase of the second meiotic division, not the first.
**Option E:** While the statement about the first polar body is true, the context provided in the question points towards the specific stage at which the primary oocyte and secondary oocyte arrest, making this choice less directly relevant to the primary question being asked.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the first meiotic division is completed just before ovulation, and the second meiotic division is completed only if fertilization occurs. This unique process of oogenesis highlights the complex regulation of female reproductive cycles.

**Correct Answer:** a) Primary oocyte arrests in prophase of 1st meiotic division