UPSC Civil Services Model Paper 4

Autotrophs manufacture their own food.
The most known example is plants that fulfill their carbon and energy requirements by photosynthesis.
Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a by-product of photosynthesis. Fungi, Protozoa, and Virus do not manufacture food.
So, options 1, 2, and 4 are NOT correct