Logical Sequence of Words Questions

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
REASONABLE

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

Leaf, Caterpillar, Frog, ?

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

Troposphere, Stratosphere, Mesosphere, ?

Rearrange the jumbled letters to make a meaningful word and then select the one which is different.

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
RECIPROCATE

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
Legislator

If the letters in the word BACKFIELDS are arranged as in the English alphabetical order, then which letter will be to the second right of the letter 'F', after the rearrangement?

From the given alternative words, select the word which cannot be formed using the letters of the given word:

LEGALIZATION