Select the most appropriate option to fill in the blank.
Many trees have growth rings that we can count and measure to ________ out how old they are and how fast they are growing.

Correct option is D

The correct word to fill in the blank is (d) find.
Correct sentence:
...we can count and measure to find out how old they are...
Explanation:
The phrasal verb “find out” means to discover or learn something, which fits the context of determining tree age and growth.
Meaning of "Find out":
· English: Discover, determine.
· Hindi: पता लगाना ✅
Meanings of all other options:
· Bring out: To publish or produce.
Hindi: प्रकाशित करना ❌
· Search out: To look for.
Hindi: ढूंढ़ना ❌
· Look out: Be careful or alert.
Hindi: सावधान रहना ❌