I devote much of time . . . . . . . . writing.

The correct answer is to.

The preposition to is used to indicate the purpose or goal of an action. In this case, the speaker is saying that they devote much of their time to writing. This means that writing is their goal or purpose.

The other prepositions are not as appropriate in this context.

• The preposition in is used to indicate a location or position. In this case, it would not make sense to say that the speaker devotes much of their time in writing.
• The preposition on is used to indicate a surface or area. In this case, it would not make sense to say that the
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