Correct option is A
The correct option to substitute the highlighted segment in the sentence "An educated lady makes a better mother than an uneducated one." is (a) No substitution required
· The sentence as written is grammatically correct. "Makes a better mother" appropriately uses the singular verb "makes" to match the singular subject "An educated lady."
· The comparative form "better" is also properly used to compare an educated lady to an uneducated one, suggesting a preference or superiority in some aspect of mothering.