The 3 basic trigonometric functions are: sine, cosine, and tangent.
The reciprocal of sine is: `1/sin x = csc x`
csc = cosecant
The reciprocal of cosine is: `1/cosx = sec x`
sec = secant
The reciprocal of tangent is: `1/tanx = cot x`
cot = cotangent
Therfore the 3 reciprocals are: secant, cosecant, and cotangent = choice"d"