For this question, choose the option opposite in meaning to the word or phrase in italics. The scientist conducted a meticulous experiment.

Meticulous means showing great attention to detail; very careful and precise. A meticulous experiment is one conducted with painstaking accuracy and thoroughness.

The word opposite in meaning is careless, which means not giving sufficient attention or thought to avoiding harm or errors. A careless experiment would be one conducted without proper attention to detail - the direct opposite of a meticulous one.

The other options are synonyms of meticulous, not antonyms:

• detailed means involving many carefully considered parts - similar to meticulous.
• thorough means complete with regard to every detail - similar to meticulous.
• careful means making sure to avoid potential problems or dangers; giving close attention - essentially the same as meticulous.

This question requires recognising that three of the four options actually share the meaning of the italicised word, while only one is its opposite.