a. Almost each visitor stopped and stared.
b. I go to the dentist every six months.
c. The entire building has recently been renovated.
Identify the incorrect sentence from the above.

The correct answer is Option A (Only a).

Key Points:
• 'Almost', 'nearly', 'virtually', and 'practically' modify 'every', NOT 'each' (e.g., 'almost every visitor', not 'almost each visitor').
• Sentence b: 'every six months' is a standard, correct expression of recurring time interval.
• Sentence c: 'The entire building...' is grammatically flawless.
• Option 1 (Only a).
• Sentence a is incorrect because adverbs like 'almost' or 'nearly' must precede 'every', not 'each'. The correct sentence is: 'Almost every visitor stopped and stared'.
• Key Takeaway: Use 'almost every' instead of 'almost each', as adverbs of degree modify 'every'.