Its A. it prevents sperm from reaching the egg and fertilizing it.
Answer is number 1........
When we discuss superposition in biology term then its principle tells that one by one rocks or sediments settles.The superposition mean that the older rocks or sediments place below all newly coming sediments or rocks place on first layer so layer over layer formation is called superposition.
It is part of our nervous system and uses stimuli to respond to an event that is happening. The five senses are motor receptors making you move your muscles to respond to that event that is happending