Usage of 'that of'

English as a Second Language English Vocabulary, Grammar and Idioms
1

Can someone please tell me which one of the following sentences is correct?

  1. His voice is strikingly similar to Mel Gibson’s
  2. His voice is strikingly similar to that of Mel Gibson
  3. His voice is strikingly similar to that of Mel Gibson’s
2

.
These are:

  1. His voice is strikingly similar to Mel Gibson’s
  2. His voice is strikingly similar to that of Mel Gibson.
    .
3

His voice is strikingly similar to that of Mel Gibson’s Christ. :lol: