Find the Dimensions of the Rectangular Box with Largest Volume $294$

Multiple Choice

Find the dimensions of the rectangular box with largest volume if the total surface area is given as $294$ $\mathrm { cm } ^ { 2 }$ .

A) $14$ cm, 1.75 cm, 1.75 cm
B) $21$ cm, $14$ cm, 1.75 cm
C) $294$ cm, $7$ cm, $7$ cm
D) $7$ cm, $7$ cm, $7$ cm
E) $14$ cm, $14$ cm, 3.5 cm