The correct option is D 171
Number of days after 10th January and before 20th June:
January = 21 days (31 - 10)
February = 29 days (2020 is a leap year)
March = 31 days
April = 30 days
May = 31 days
June = 29 days
So, total number of days between 10th January and 20th June is, 21 + 29 + 31 + 30 + 31 + 29 = 171 days.