Which one of the following can cause the interior of the neuron to have a momentary positive charge?
(a) opening of potassium leak channels
(b) activity of the na/k atpase
(c) opening of voltage gated sodium channels
(d) opening of voltage gated potassium channels

(c) Opening of voltage gated sodium channels

Explanation:

The firing of action potential leads to a quick opening of voltage-gated Na+ channels and slow opening of K+ channels. The opened voltage-gated Na+ channels allow the Na+ to enter the neuron and cause depolarization.

The interior of the cell becomes positive quickly. As the rising potential passes 0 mV, the voltage-gated Na+ channels are inactivated and the entry of the Na+ stops while the K+ channels are fully opened to repolarize the membrane again.

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

nucleus

would be most reasonable answer tbh