The correct answer is: B. 61 days
Average collection period is the average number of days it takes a company to collect its outstanding receivables. It is calculated by dividing the total amount of accounts receivable by the average daily sales.
In this case, the total amount of accounts receivable is Rs 90,000 and the average daily sales is Rs 5,40,000 / 365 = Rs 1,481.48. Therefore, the average collection period is 90,000 / 1,481.48 = 61 days.
Option A is incorrect because it is the number of days in a month, not the average collection period. Option C is incorrect because it is the number of days in a quarter, not the average collection period. Option D is incorrect because it is the number of days in a year, not the average collection period.