Answer:

The correct answer is option 'B', farmer's wife.

Explanation:

The line "it is a baby mongoose" was said by the farmer's wife. To understand the context behind this statement, let's break it down into a few key points:

1. The Scenario:
In the given question, we are given a line: "it is a baby mongoose." This line implies that someone is observing and identifying a creature, specifically a baby mongoose.

2. The Participants:
To determine who said the line, we need to consider the different characters involved in the scenario. The options provided are:
a) Farmer
b) Farmer's wife
c) Farmer's son
d) His friend

3. The Speaker:
Out of the given options, the most likely speaker of the line "it is a baby mongoose" would be the farmer's wife. This is because the farmer's wife is typically involved in domestic activities and may have encountered the creature in or around the house. Additionally, the wife often takes care of the household chores and may be more familiar with the animals present on the farm.

4. The Role of Others:
While the other options, such as the farmer, farmer's son, or his friend, could also potentially identify the creature, the context of the question suggests that it is the farmer's wife who says the line. The farmer's son and his friend may have been present during the observation, but they are not mentioned as the ones identifying the creature.

Therefore, based on the given options and the context of the scenario, the correct answer is option 'B', farmer's wife.