Which one of the following is the terminal electron acceptor?

Given below are two statements.
Statement-$I$: Cytochrome $c$ is a small, copper-containing protein loosely attached to the inner membrane.
Statement-$II$: Cytochrome $c$ acts as a mobile electron carrier transferring electrons between complex $I$, $II$, and $IV$.
In the light of the above statements, choose the correct answer from the options given below.

Cytochrome is found in

The last or terminal cytochrome in the respiratory chain is

Hibernating animals have tissues containing mitochondria with a membrane protein that accelerates electron transport while blocking the synthesis of $ATP$. What is the consequence of this?

Cytochromes are .........