Answer:
C
Step-by-step explanation:
The sum to n terms of a geometric sequence is
[tex]S_{n}[/tex] = [tex]\frac{a_{1}(r^n-1) }{r-1}[/tex]
Here a₁ = 4 and r = - 3, thus
[tex]S_{6}[/tex] = [tex]\frac{4((-3)^6-1)}{-3-1}[/tex]
= [tex]\frac{4(729-1)}{-4}[/tex] = - (729 - 1) = - 728 → C
