In the following question, out of the four alternatives, select the alternative which will improve the underlined part of the sentence. In case no improvement is needed, select “No improvement”.You should to read the newspaper regularly if you want to be well-informed.

The correct answer is option 1, i.e., Ought to. The sentence uses the incorrect MODAL verb form 'should to'. The verb after the underlined part is the simple present tense verb 'read', suggesting that it is part of a to-infinitive. So, 'to' is necessary. The context of the sentence suggests that it is a MORAL advice or the correct way to do something. Whenever the sentence suggests an advice, an expected or desired STATE; the modal verb 'ought' is used. e.g. You ought to respect the elders. So, here, the correct modal verb becomes 'ought to'. 'Have to' also makes the sentence meaningful. But; 'have to' indicates a COMPULSION and not an advice; so it is not appropriate here. Note: 'Ought to' and 'should' can be generally used synonymously. Thus, the rectified sentence is: You ought to read the newspaper regularly if you want to be well-informed.