Table:
text: AR-15 variants
AR series models
AR series models
Colt_model_no_ Name_ Stock Fire_control Rear_sight Forward_assist Case_deflector Barrel_length Barrel_profile Barrel_twist Hand_guards Bayonet_Lug Muzzle_device
AR6320 AR-15 Lightweight 4th Generation S-1 A1 Yes Yes 16 in. A1 1:9 Short Ribbed Yes A2
AR6450 AR-15 9mm Carbine 4th Generation S-1 A1 No Removable 16 in. A1 1:10 Short Ribbed Yes A1
AR6520 AR-15A2 Government Carbine 4th Generation S-1 A2 Yes Yes 16 in. A1 1:7 Short Ribbed Yes A2
AR6520SP AR-15A2 Government Carbine 4th Generation S-1 A2 Yes Yes 10 in. A2 1:7 Short Ribbed Yes A2
AR6525 AR-15A2 Government Carbine 4th Generation S-1 A2 Yes Yes 16 in. A2 1:9 Short Ribbed Yes A2

text: AR-15 variants
AR series models
AR series models
Colt_model_no_ Name_ Stock Fire_control Rear_sight Forward_assist Case_deflector Barrel_length Barrel_profile Barrel_twist Hand_guards Bayonet_Lug Muzzle_device
AR6721 AR-15A3 Tactical Carbine 4th Generation S-1 Flattop Yes Yes 16 in. HBAR 1:9 Short Ribbed Yes A2
AR6721SP AR-15A3 Tactical Carbine 4th Generation S-1 Flattop Yes Yes 10 in. HBAR 1:9 Short Ribbed Yes A2

Question: Name the handguards of the government carbine ar-15a2 and the barrel twist of the AR series models of 1:9 among the AR-15 variants. ?