The correct answer is: Only conclusion I follows.
The first statement is an “All A are B” statement. The second statement is an “I is B” statement. In syllogistic logic, the only valid conclusion that can be drawn from these two statements is “I is A”. This is known as the “Modus Ponens” rule of inference.
In other words, we can conclude that Sachin is a boy, because all boys are honest, and Sachin is honest. However, we cannot conclude that all honest persons are boys. This is because there may be other people who are honest, but who are not boys. For example, a girl could be honest.
Therefore, the only valid conclusion that can be drawn from the given statements is “Sachin is a boy”. Conclusion II, “All honest persons are boys”, is not a valid conclusion.