Step 1: Recall gestation period in cattle.
Gestation = time from conception to calving. For cows, the average gestation period is 283–290 days (about 9.5 months).
Step 2: Analyze the options.
(A) 310 days – higher than average, applies more to buffalo.
(B) 300 days – still longer than normal for cows.
(C) 290 days – correct average for cows.
(D) 280 days – close but slightly lower.
Step 3: Conclusion.
Therefore, the correct gestation period of cows is about 290 days.