Respuesta :

[tex]a_1=13\\\\a_2=21\\\\a_3=a_1+a_2=13+21=34\\\\a_4=a_2+a_3=21+34=\boxed{55}\\\\a_5=a_3+a_4=34+55=\boxed{89}[/tex]

Answer C.
I think it's A
since 21 -13 = 8 And 34-21= 13 so u continue the pattern by doing 34 + 8 then that will equal 42 so then you add 42 + 13 which would give you 55