In the following questions, a sentence is given with four highlighted words in it. It is then followed by four alternatives that may/may not represent the correct meaning of these highlighted words. Choose the option that represents the CORRECT meaning of the highlighted word and mark it as your answer. If none of the options is correct, choose option E (None of these) as your answer. New medical treatments are being vigorously tested by researchers to ensure that potential side effects remain negligible and patient well-being is safeguarded .