The type of clause in the underlined part of the sentence is: Adjective clause OPTION 2

The sentence contains a relative clause (who I met at the bus stop) that provides additional information about the noun "man." This type of clause is also referred to as an adjective clause because it functions like an adjective, describing or modifying the noun..

An adjective clause is a dependent clause that modifies a noun. In this case, the underlined part, "who I met at the bus stop," modifies the noun "man" by giving us more information about him.