Answer:
The age of the tree in scientific notation form is
.
Option (D) is correct .
Explanation:
As given in the question
A tree is 3,212 years old.
Now write 3212 in the scientific notation form .
= 3212
Multiply and divided the above expression by 1000 .

Simplify the above

Thus it is written as

Therefore the age of the tree in scientific notation form is
.
Option (D) is correct .