Let $$a,b$$ and $$c$$ be real numbers such that $$2a^2-bc-9a+10=0$$ and $$4b^2+c^2+bc-7a-8=0$$. Then the set of real values that $$a$$ can take is given by

A

$$[1,4.2]$$

B

$$(-\infty,1)\cup(4.2,\infty)$$

C

$$(1,4.2)$$

D

$$[1,4.2)$$