"Friendly" is an adjective, and adjectives can't directly modify a verb like "spoke", so describing how someone spoke requires an adverbial phrase such as "in a [adjective] manner".
The correctly improved sentence reads "in a very friendly manner", using "friendly" as an adjective describing "manner" and "very" as an intensifier in front of it.
Options 1 and 4 change the intended meaning, and option 2 uses the wrong preposition "with" instead of "in", which leaves option 3 as the correct improvement.