Answer:
They block sperm from reaching an egg.
Explanation:
Unlike the traditional birth control pill, the mini-pill has only the hormone, progestin. Taken daily, the mini-pill thickens cervical mucus and prevents the sperm from reaching the egg.
When you swallow, a flap called the epiglottis moves to block the entrance of food particles into your larynx and lungs. The muscles of the larynx pull upward to assist with this movement. They also tightly close during swallowing. That prevents food from entering your lungs.
The answer among the choices is letter A. Sterols is a lipid that doesn't contain a glycerol backbone because it is mostly unsaturated. It can be commonly found on fungi, plants, and animals as an important organic molecule. I hope my answer helps you.
It has to be d. The others wouldn't really make sense.