Find out the incorrect sentences.

Certainly! Let's break down the explanation for each sentence:

ক. Karim resigned from his post.

- This sentence is correct. It follows the standard usage of the verb "resigned" with the preposition "from" when referring to leaving a position or job. The preposition "from" is used to indicate the origin or starting point of the action.

খ. Karim resigned his post.

- This sentence is also correct, though it is a bit less common. In this case, the verb "resigned" is used directly with the object "his post" without a preposition. While "resigned from his post" is more widely accepted, using the possessive form without the preposition is grammatically acceptable.

গ. Get the picture hanged in your room.

- This sentence is incorrect. The mistake lies in the use of the verb "hanged." When referring to placing a picture on the wall, the correct form is "Get the picture hung in your room." "Hung" is the past participle of the verb "hang" when used in this context.

ঘ. Get the picture hung in your room.

- This sentence is correct. It uses the correct form of the verb "hang" in the past participle form, which is "hung" in this context.

In summary, the incorrect sentence (গ) had an error in the choice of the past participle form of the verb "hang." It should be "Get the picture hung in your room" instead of "Get the picture hanged in your room."