The verb “絞る” (しぼる) means “to squeeze” or “to wring.” In the context of the sentence, “ぞうきんはよく絞って使いなさい” means “Make sure to wring the mop well before using it.” The correct reading of “絞る” in this context is “しぼる,” which is conjugated to “しぼって” in the te-form.
ねじって: This is the te-form of “捻る” (ねじる), which means “to twist” or “to wring,” but it is not the correct reading for “絞る.”
しぼって: This is the correct te-form of “絞る” (しぼる), meaning “to squeeze” or “to wring.”
しめって: This is not a correct te-form for any common verb related to the context.
ひねって: This is the te-form of “捻る” (ひねる), which means “to twist” or “to wring,” but it is not the correct reading for “絞る.”