• Assertion (A) is True: Hatchability of eggs laid during long laying sequences (clutches of $\gt 4\text{--}6\text{ eggs}$) is significantly higher than that of eggs from short 1- to 2-egg sequences.
• Reason (R) is True: The first egg of a sequence experiences prolonged oviduct holding time, delayed pre-ovulatory aging, and increased pre-incubation embryonic development, which depresses hatchability. In long sequences, a far smaller proportion of eggs suffer from this pre-incubation delay.
• Relationship: (R) correctly explains the physiological basis of (A).

Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)