In this question a statement is given which is followed by two assumptions numbered I and II. You have to consider the statement and the following assumptions and decide which of the assumption (s) is/are implicit in the statement.

Statement: The boy is too honest not to speak the truth.

Assumptions:

I. Very honest boys also tell lies.

II. Dishonest boys also speak the truth.

If neither I nor II is implicit.

We first need to read the statement carefully and then see what immediate assumptions can be drawn based on our first reading. The next step is to look at the assumptions given in the options, analyze them and see if they seem relevant with respect to the information/data provided to us.

The statement only implies that if a boy is very honest, it would be impossible for him to speak a lie.

Assumption I is exactly the opposite of what is conveyed through the statement. Hence it is not implicit.

Assumption II talks about dishonest boys who are not being talked about in the statement. Hence, this assumption is also not implicit.

Hence, neither of them is implicit.

Thus, the correct answer is option 4.