First choose correct option and explain step by step by with reason

1A) Guide replacement is being discussed. Technician A says to match guide materials to valve stem materials when selecting valve guide inserts or liners. Technician B says all guides are removed toward the combustion chamber. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B 13) Installing guide inserts is being discussed. Technician A says to measure the amount the guide protrudes from the head casting so the new guides can be installed to the same height. Technician B says to cut a chamfer on the insert if the insert does not have one. Who is correct? A. A only B. B only C. Both A and B D. NeitherA nor B 1C) Reconditioning OHC cylinder heads is being discussed. Technician A says cylinder head warpage does not affect camshaft bearing bore alignment. Technician B says if the head is to be straightened by heat, brass shim stock equal to the thickness of the total amount of warpage is placed under each end of the cylinder heads. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B 1D) Reconditioning valve seats is being discussed. Technician A says if the seat is too narrow, it is corrected by using the same degree stone as the valve seat angle. Technician B says if the valve seat is too wide, throat the seat. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B 1E) Technician A says that valve guides can be pearlized to restore them to their original condition. Technician B says that worn valve guide inserts can be pressed or driven out and new ones installed. Who is correct? A. A only B. B only C. Both A and B D. NeitherA nor B 1F) Technician A says to try to take as much material off the valve stem tip as you did off the face. Technician B says you should put a light chamfer on the tip. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B 1G) Technician A says that the valve guide must be clean and not worn excessively before repairing valve seats. Technician B says to pick a guide pilot that slides down to the bottom of the guide easily. Who is correct? A. A only B. B only C. Both A and B D. Neither A nor B1H) A valve seat is too wide. The area of contact is high toward the head of the valve. The seat should be cut with a stone. A. 30-degree B. 44-degree C. 45-degree D. 60-degree