A logical problem begins with the statement, "Suppose it was possible to move backward but not forward in a time machine" Most of the students in the class can solve the problem easily. They acquired this ability in the course of this school year. The students in this class appear to be at what stage of development?

Formal operational stage

Explanation:

 The formal operational stage is one of the type of cognitive development stage in which the adolescent start entering in this stage approx 12 years children and they start thinking in the form of abstract way by manipulating different types of thoughts and ideas.

 According to the given question, in the above given statement the students in the class are appearing in the formal operational stage of the development as they are able to resolve the various types of problems easily.

  Therefore, Formal operational stage is the correct answer.    

pretty sure a is right

answer; bonds; i believe this is the correct answer good luck