ANSWER
C. 210
EXPLANATION
The given binomial expression is
[tex] (x+y)^{10}[/tex]
Comparing to the general binomial expression,
[tex](a+b)^{n}[/tex]
we have
[tex]n = 10[/tex]
Since we want to find the coefficient of
[tex] {x}^{6} {y}^{4} [/tex]
[tex]r = 4[/tex]
Using the binomial theorem, the coefficient is
[tex]nC_r = 10C_4 = 210[/tex]
The correct choice is C.