**Core Concept**
The post-coital test evaluates sperm motility and viability in the female reproductive tract. A non-motile sperm in cervical smear but motile sperm in posterior fornix indicates a failure of sperm to reach or survive in the cervical mucus, pointing to issues in coital technique rather than underlying male or immune pathology.

**Why the Correct Answer is Right**
In a post-coital test, if sperm are non-motile in the cervical smear (indicating poor passage or exposure), but motile sperm are found in the posterior fornix (a site distal to the cervix), it suggests that sperm were present in sufficient quantity and were capable of motility, but failed to progress through the cervical mucus. This discrepancy is best explained by **faulty coital practice**, such as improper timing, inadequate ejaculation, or insufficient semen deposition in the vagina. The presence of motile sperm in the posterior fornix confirms sperm viability, but the absence in the cervical smear implies poor contact or technique, not a pathological cause.

**Why Each Wrong Option is Incorrect**
Option B: Immunological defect would typically show sperm antibodies in serum or cervical mucus, causing agglutination or reduced motility, not a selective absence in cervical smear.
Option C: Hypospadias is a congenital malformation of the urethral opening, unrelated to post-coital test findings.
Option D: Azoospermia refers to absence of sperm in semen, which would show no sperm in posterior fornix, not motile sperm in that site.

**Clinical Pearl / High-Yield Fact**
In post-coital tests, a discrepancy between cervical and posterior fornix findings is often due to technical errors. Always ensure proper coital technique—ejaculation should occur immediately after intercourse, and the female partner should remain in a supine position for at least 20 minutes post-coitus.

✓ Correct Answer: A. Faulty coital practice