None of these. All of these functions are defined as ratio of trigonometric functions.
Trigonometric functions have infinite zeroes, so when you put them in the denominator, they lead to infinitely many points of ill-definition.
Specifically, we have:

which is undefined at


which is undefined at


which is undefined at


which is undefined at

1= -6
2= -5
3= -4
4= -3
5= 0
6= 3
Answer:
3 miles per hour
Step-by-step explanation:
The units are ordered smallest to largest from top to bottom:
Picometer (pm) = 1 x 10⁻¹² meters
Nanometer (nm) = 1 x 10⁻⁹ meters
Micrometer (um) = 1 x 10⁻⁶ meters
Millimeter (mm) = 1 x 10⁻³ meters
Centimeter (cm) = 1 x 10⁻² meters
Decimeter (dm) = 1 x 10⁻¹ meters
Meters (m) = 1 meter
Kilometers (Km) = 1 x 10³ meters