A sentence/a part of the sentence is underlined. Four alternatives are given to the underlined part which will improve the meaning of the sentence. Choose the correct alternative and click the button corresponding to it. In case no improvement is needed, click the option corresponding to 'No improvement'. Many controlled studies have examined the affects of caffeine on the brain, demonstrating that caffeine can temporarily improve mood. Correct Answer Effects of The word affect is used as verb only and effect is used as both verb and noun. Affect means to influence something or someone. Effect, when used as a noun, means the result of an influence. When used as a verb, effect means to bring about or cause something to occur. Examples – More people should be made aware of the fatal effects of smoking. (effect as noun) The medicines have affected him severely. The NGO was unable to effect any social change. (effect as verb - meaning the NGO was not able to bring about any social change) Therefore, the correct answer is option 2. Correct sentence - Many controlled studies have examined the effects of caffeine on the brain, demonstrating that caffeine can temporarily improve mood Note – the other options do not fit well in the sentence. The phrase 'problems of' cannot be used as the sentence suggests a positive impact when caffeine is consumed.