Option 1: Strong -> Opposite of tenuous; means having great strength, solid, and substantial.
Option 2: Delicate -> Synonym of tenuous; means fragile, weak, or easily broken.
Option 3: Feeble -> Synonym of tenuous; means lacking strength or weak.
Option 4: Common -> Unrelated to the core meaning of tenuous (weak/thin).
Hence, Option 1: Strong -> Tenuous means weak, slight, or lacking substance, so its antonym is "strong," which conveys power, solidity, and firmness -> correct