In this statement about trade union leadership being in the hands of politicians, there are two assumptions that can be made.

Assumption I states that trade unions have leaders. This assumption is implied in the statement because it mentions trade union leadership, which suggests that there are individuals who hold positions of leadership within trade unions. Therefore, Option 1, which states that only I is implied in the statement, is not correct.

Assumption II states that leaders in trade unions are generally politicians. This assumption is also implied in the statement. It suggests that the individuals who hold leadership positions in trade unions are typically politicians. This could be based on the observation that many leaders in trade unions have political affiliations or backgrounds. Therefore, Option 2, which states that only II is implied in the statement, is not correct.

Since both assumptions I and II are implied in the statement, the correct answer is Option 3 - Both I and II are implied in the statement.