Step 1: Grammatical error identification.
- Sentence A: Incorrect spacing after colon in "9: 00 a.m.". Corrected to "9:00 a.m.". - Sentence B: Redundant "off of" in "Keep off of the grass". Corrected to "Keep off the grass." - Sentence C: Correctly compares two car speeds. - Sentence D: Correct; "angry at" is acceptable informally. - Sentence E: Correct; proper comparative construction.
Step 2: Combination evaluation.
- Option 1 (A & B): Both A and B are incorrect.
- Option 2 (B & C): C is correct.
- Option 3 (C & D): D is correct.
- Option 4 (D & E): Both D and E are correct.
- Option 5 (A & E): E is correct.