State the Degree of Each Expression $3 x^{4}+4 y^{6}$ (B) $7 x^{2}+3 x-5$

State the degree of each expression.
(a) $3 x^{4}+4 y^{6}$
(b) $7 x^{2}+3 x-5$
(c) $-9 x y^{2}+4 y^{3}$