When the effects of genes add up to make the phenotype, they are called additive genes.
Answer:
That would be option D. A motor.
Explanation:
The gestation period in cats stays for approximately 66 days and in every cycle a cat give birth more than 2 babies so if all cats are producing kittens at this rate, a prediction can be made that there will be lots of cats in our ecosystem. There will be cats everywhere if the number is not controlled.
As mentioned earlier, cats can starts reproducing at a young age of 6 months and right after delivery can get pregnant.