15x plus 14y plus 3x plus 7y simplified is:

(1 point)
Responses

39xy
39 xy

29x + 10y
29 x + 10 y

29xy + 10xy
29 xy + 10 xy

18x + 21y

The simplified form of 15x + 14y + 3x + 7y is 18x + 21y.