How do fungi digest their food sources?

A. by engulfing food particles and digesting them in vacuoles
B. by secreting enzymes externally, directly into their surrounding environment
C. by extending hyphae into a food source (e. g. an animal carcass)
D. by funneling food particles through septa, which break down larger molecules

Option B, by secreting enzymes externally, directly into their surrounding environment

Explanation:

Fungi are not able to engulf their food just like bacteria. They do not have stomach or digestive system/organ. In fact, the digestion in fungi is external which means they release digestive enzymes to digest the surrounding organic food externally. After the food digestion gets complete, essential elements are released in the environment which are then taken up by the Fungi for  

Hence, option B is correct

answer; ///(b) it is composed of four protein chains and four heme groups;