What is the correct pronoun to use with conocio?

Question

John conoció a CIRILO. ______ conoció. Do you use lo, la, los, or las?

Answer 1

Lo given the only option of direct object pronouns. (in some regions the leísmo is acceptable and Le might be used).

Also that sentence might sometimes be written as John lo conoció a Cirilo.

(I'm assuming that Cirilo is a masculine name-perhaps Cyril in English.)