The correct answer is option 4, Carotene. Cow`s milk appears slightly yellow in color due to the presence of carotene. Carotene is a pigment found in plants and is passed on to the milk when cows consume plant-based food. Carotene is a precursor to vitamin A and is commonly found in foods like carrots, pumpkins, and leafy greens. When cows consume these foods, the carotene is absorbed into their bloodstream and distributed throughout their bodies, including the mammary glands where milk production occurs. As a result, the carotene gives cow`s milk a slightly yellow color. It is important to note that the amount of carotene in milk can vary depending on the cow`s diet and other factors.