💡 Detailed Explanation
The correct choice is '食べさせました' (made/let eat), which is the past polite causative form of '食べる' (to eat). The structure '[Causer] は [Causee] に [Object] を [Causative Verb]' indicates making or letting someone do an action. Sentence translation: 'The mother made her child eat vegetables.' The other choices are: '食べました' (active: ate), '食べられました' (passive/potential: was eaten / could eat), and '食べてもらいました' (received the favor of eating, which would imply the child did the mother a favor by eating, less fitting than causative here).