Answer:
The following are the solution to the given points:
Step-by-step explanation:
for point A:


The set A is not part of the subspace 
for point B:


The set B is part of the subspace
for point C:

In this, the scalar multiplication can't behold

∉ C
this inequality is not hold
The set C is not a part of the subspace
for point D:

The scalar multiplication s is not to hold
∉ D
this is an inequality, which is not hold
The set D is not part of the subspace 
For point E:

The
is the arbitrary, in which
is arbitrary

The set E is the part of the subspace
For point F:

The
arbitrary so, they have
as the arbitrary 
The set F is the subspace of 
my guess would be c. but id wait for someone else to answer just to be sure
In this question it basically wants you to leave Y alone in a side of the equation.
In this case,
For 3y=c

For Ay=w

For Y/c=w
Y=cw
For y/a=2c
y=2ac
For a=y+p
y=a-p
For C=y-k
y=C+k
the answer would be 161.6 mph