This sentence is complete as is.
The question is asking about the weather. Based on image b, the weather is rainy.
Answer: It is raining
This sentence is a statement about the weather. Based on image c, the weather is sunny.
Answer: It is not raining
This sentence is a suggestion. Based on image d, the sun is shining and the umbrella is open. The character is not using the umbrella for shade, but rather relaxing with it.
Answer: Never mind! Don't use my umbrella for the sun!