Answer:
The correct option is B.
The standard time for this job would be 12.10 minutes.
Explanation:
Element  |  St(min)  |   RF    |  AOT  |   NT  Â
  1      |  54.64   |   1.05   |  2.73  |  2.86
  2     |  49.67   |   1.10    |  2.48  |  2.72
  3     |  42.98   |   0.95   |  2.14   |  2.03
  4     |  51.37   |   0.95   |  2.56  |  2.43
The standard time for the job is calculated by
Standard time = Total normal time*(1 + allowance factor)
Where Normal time is given by
Normal time = Average observation time * Rating Factor (RF)
Where Average observation time is given by
Average observation time = St(min)/number of job cycles
number of job cycles = 20
Total Normal time = 2.86 + 2.72 + 2.03 + 2.43
Total Normal time = 10.04 minutes
Standard time = 10.04*(1 + 0.20)
Standard time = 12.04 minutes
Therefore, the correct option would be B, the standard time for this job would be 12.10 minutes.