Which of the following is incorrect according to Griffith experiments ?
(A) S-Strain `to ` Inject into mice `to` mice live
(B) R-Strain `to ` Inject into mice `to` mice live
(C ) Heat-killed S-Strain `to` Inject into mice `to` mice live
(D) Heat killed S-Strain + R-Strain `to` Inject into mice `to` mice die

Options

A. A and D
B. Only A
C. B and C
D. Only B

Answer

To solve the question regarding Griffith's experiments, we need to analyze each option based on the findings from his research on Streptococcus pneumoniae, which involved two strains: the virulent S-strain and the non-virulent R-strain.

### Step-by-Step Solution:

1. **Understanding the Strains**:
- The S-strain (smooth strain) is virulent and causes disease in mice.
- The R-strain (rough strain) is non-virulent and does not cause disease in mice.

2. **Analyzing Each Option**:
- **Option A**: S-Strain injected into mice results in mice living.
- This statement is **incorrect**. When S-strain is injected into mice, they die because the S-strain is virulent.

- **Option B**: R-Strain injected into mice results in mice living.
- This statement is **correct**. The R-strain is non-virulent, so the mice survive.

- **Option C**: Heat-killed S-Strain injected into mice results in mice living.
- This statement is **correct**. The heat-killed S-strain does not cause disease, so the mice survive.

- **Option D**: Heat-killed S-Strain + R-Strain injected into mice results in mice dying.
- This statement is **correct**. The combination of heat-killed S-strain and live R-strain leads to the transformation of the R-strain into a virulent form, causing the mice to die.

3. **Conclusion**:
- The only incorrect statement according to Griffith's experiments is **Option A**.

### Final Answer:
The incorrect statement according to Griffith's experiments is **Option A**: S-Strain injected into mice results in mice living.