Fruit of the LoomBoy's Cotton Boxer Brief Underwear (Pack of 10)

The size chart is men’s and the department reads men’s but the description says boys... which sizing is this for boys or men?

Will x large fit a 5year old boy

I ordered the monster style 10 pack in 4t/5t and received 2t/3t twice (replacement) does it only come in 2/3t in that design even though it says 4t?

What numbered size in boys clothes (not toddler) does Medium correspond to?