Solve the Problem $\mathrm { R }$ Of an Earthquake Is Based on the Features of the }

Multiple Choice

Solve the problem.
-The Richter scale magnitude $\mathrm { R }$ of an earthquake is based on the features of the associated seismic wave and is measured by $\mathrm { R } = \log ( \mathrm { a } / \mathrm { T } ) + \mathrm { B }$ , where a is the amplitude in $\mu \mathrm { m }$ (micrometers) , $\mathrm { T }$ is the period in seconds, and B accounts for the weakening of the seismic wave due to the distance from the epicenter. Compute the earthquake magnitude $\mathrm { R }$ when $\mathrm { a } = 210 , \mathrm {~T} = 5$ , and $\mathrm { B } = 3.5$ . (Round to the nearest ten-thousandth.)

A) $8.6232$
B) $1.6232$
C) $5.1232$
D) $1.8768$