The Amount of Time It Takes for a Pendulum to Swing

Multiple Choice

The amount of time it takes for a pendulum to swing "to-and-fro" through one complete cycle is called the "period" and is calculated using the following equation: $T = 2 \pi \sqrt { \frac { L } { g } }$ where $T =$ period in seconds
$L =$ length of pendulum
$g =$ gravitational acceleration, $9.8 \mathrm {~m} / \mathrm { s } ^ { 2 }$ What is the appropriate unit for L if the preceding equation is to be homogeneous in units?

A) meters
B) liters
C) $\mathrm { m } / \mathrm { s } ^ { 2 }$
D) seconds