The logic followed is: Logic: Relation between two words has to be found out. For, "Extrovert" and "Introvert" Antonym of Extrovert is Introvert. Now, we have to find antonym of "Timid" Meaning: someone who has a lack of courage. For, "Option1: Shy".→ False As it is a synonym of Timid. For, "Option2: Dwarf".→ False. Dwarf word is not related to Timid. For, "Option3: Toxic". → False. Toxic is not related to Timid. For, "Option4: Bold".→ True. Meaning: Someone who is confident. Hence, it is the antonym of "Timid". Hence, the correct answer is "Bold".