Explanation:

- Option 1: "were being felt"

- This implies past continuous action. It suggests the effects were ongoing in the past but may not be now.

- Option 2: "are being felt"

- This indicates present continuous action. It means the effects are ongoing and happening at present.

- Correct Answer for the context.

- Option 3: "has been felt"

- This uses present perfect tense, indicating that the effects started in the past and have relevance to the present. It doesn’t imply ongoing action.

- Option 4: "is being felt"

- This is present continuous in the singular form. It suggests only one effect is felt now, but "effects" is plural.