Answer:
Vitamin A will pass through proteins to go from outside the cell to inside.
Explanation:
Many substances passively enter and leave cells through the plasma membrane. This means that such substances move freely without the cell having to expend energy. This is the case of oxygen gas and carbon dioxide, for example.
Other substances enter and leave cells actively. In this case, the cell uses energy to promote their transport across the plasma membrane. In this transport there is participation of special proteins, called carrier enzymes. Fat molecules, for example, are transported this way. Vitamin A is also transported like this as it is a fat soluble vitamin, ie it is a vitamin that dissolves in fat.
