Cotton and pigeon pea

Four letter-clusters have been given out of which three are alike in some manner and one is different. Select the one that is different.

Three of the following four number-clusters are alike in a certain way and thus form a group. Which is the one that does not belong to that group?

Find the odd set of numbers from the given alternatives?

In the following question, select the odd number pair from the given alternatives.

Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the letter-cluster that is different.

Four letter- clusters have been given out of which three are alike in some manner, while one is different. Choose the odd one.

Find the odd one from the following:

Four letter clusters have been given, out of which three are alike in some manner and one is different. Select the letter cluster that is different.

Understand the logic in the given words and choose the odd one out.