Round Your Answer to the Nearest Tenth, When Appropriate $\mathrm { pH } = - \log \left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right]$

Multiple Choice

Round your answer to the nearest tenth, when appropriate. Use the formula $\mathrm { pH } = - \log \left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right]$ , as
needed.
-Find $\left[ \mathrm { H } _ { 3 } \mathrm { O } ^ { + } \right]$ if the $\mathrm { pH } = 1.4$ .

A) $2.5 \times 10 ^ { - 2 }$
B) $2.5 \times 10 ^ { - 1 }$
C) $4.0 \times 10 ^ { - 1 }$
D) $4.0 \times 10 ^ { - 2 }$