Answer:
D. joint variation
Explanation:
y = 14x/z
y is directly proportional to x and inversely proportional to y
Constant of proportionality = 14
Direct variation is given as
y = kx
Where, k = constant of proportionality
Inverse variation is given as
y = k/z
Where, k = constant of proportionality
When they are jointly combined
y = kx/z