​Identify the part which contains an error.​

Correct option is C

The error lies in option (c) “since a week.” The preposition “since” is used to refer to the starting point of an action or event, usually a specific point in time (like a date, day, or exact moment). However, “a week” is a period of time, not a specific point, so the correct preposition should be “for” instead of “since.”

Thus, the corrected phrase should be:

“for a week.”

The corrected sentence would be:

“It has been snowing in Shimla for a week now.”

Explanation:

• Since = Refers to a specific point in time (e.g., since Monday, since 2020).
• For = Refers to a duration or period of time (e.g., for two hours, for a week).

Using “since” with a period like “a week” is incorrect because “a week” is not a point in time, but a duration.