A horse is tethered to one corner of a rectangular grassy field 42 m by 26 m with a rope 16 m long. Over how much area of the field can it graze? Choose the correct choice from the following.
A) 154 cm 2  B) 308 m 2  C) 201 m 2  D) 205 m 2  E) none of these

Rationale: "area of the shaded portion = 1 ⁄ 4 × π × ( 16 ) 2 = 201 m 2 answer c"
Answer: C