Rearrange r=v/i so that it is in the form y=mx+c

R= V/I

R is resistance

V is voltage

I is current

We can multiply by I both side

I*R = (V/I)*I

I will cancel out from right side

so IR = V

we can write it

V= IR

V= RI + 0

This equation is same as Y = MX +C

here Y is V

M is R which shows slope in a graph and it is constant

C is Y intercept but it will be zero because if potential difference is zero then current will also be zero

the answer you are looking for is d. there are no holes for blood to enter or leave the system. your welcome