Incomplete question -
does not say what 'it' refers to
4 years
22 years
19 years
4 years
about 5 and a half years
Computer
two years
1886 to 1894
It took many many years
It is a bachelors course and takes minimum 3 years for completion.
It takes 164.8 years to complete one revolution to neptune around the sun
255 days