Simplify and write the result in standard form, $a+bi.$

$\frac{6-\sqrt[\phantom{2}]{-18}}{-3}$

Select one:

a$.-2+3i\sqrt[\phantom{2}]{2}$

b$.-2-i\sqrt[\phantom{2}]{2}$

C$.-2+i\sqrt[\phantom{2}]{2}$

d$.-2-3i\sqrt[\phantom{2}]{2}$