Question

I am confident ______ success. fill up with preposition​

Answer 1

I am confident of success.

Correct use of prepositions

• Prepositions are used as connectors to establish a link between nouns or proper nouns with the whole sentence.
• The sentence will be grammatically incorrect if proper punctuation is not used.
• We can also use these words to show time, location, and direction.
• Some examples of prepositions are from, upon, by, off, under, etc.

So the correct option will be of.