The table lists some inherited characteristics. Which characteristics demonstrate co-dominance?
- Ablood group ✓, colour blindness ✓, sex ✗
- Bblood group ✓, colour blindness ✗, sex ✗
- Cblood group ✗, colour blindness ✓, sex ✓
- Dblood group ✗, colour blindness ✓, sex ✗