Question

An example of an organism is

the human heart
the petals of a rose
a colony of ants
an oak tree

It's obviously not A.

Answer 1

The answer is A
Explain
Only thing that’s an organism

Answer 2

an oak tree

Step-by-step explanation:

All the other options are either parts of an organism ( rose petal and human heart) or, multiple organisms ( a colony of ants) but, an oak tree is one single living organism.