the question does not present the options, but this does not interfere with the resolution
let
x-------> the length of the garden
y-------> the width of the garden
A-------> Area of the garden
we know that
A=x*y
A=120 ft²
for x=12 ft
120=12*y-----------------> y=10 ft
but
the length of the garden to be more than 12 feetx > 12 ft
therefore
y < 10 ft
Hence
the answer is
The width of the garden must be less than 10 ft (width < 10 ft)