Answer:
The answer is option (B)
Here is the explanation...
C. The total area of the patio.
If you don't know the area you can't know how many bricks you need.
divisions between $389$ and $390$ so each division is $\frac{390-389}{10}=0.1$
A is 8 division from $389$, so, A is $389+8\times 0.1=389.8$
similarly, C is one division behind $389$ so it is $389-1\times 0.1=388.9$
and B is $390.3$
1 + sec^2(x)sin^2(x) = sec^2(x)
This becomes
1+tan^2(x) = sec^2(x) which is an identity
You could
1 + sin^2(x)/cos^2(x) = sec^2(x)
then
cos^2(x) + sin^2(x) = cos^2(x)sec^2(x)
1 = 1