**Q**
Is the following sentence factually correct?
"Diphtheria toxin is a single, 90-kDa-molecular weight protein composed of three peptide chains, fragment A, fragment B, and fragment C."
Options:
- yes
- no
**A**
no
Diphtheria toxin is a single, 60-kDa-molecular weight protein composed of two peptide chains, fragment A and fragment B.

**Q**
"Johnny Carson worked as a rich oil magnate."
Is the above claim true?
Options:
- yes
- no
**A**
no
Johnny Carson was a famous talk show host and was not in the oil business.

**Q**
Is the following a factual statement?
"Canadians perpetrated the Attack on Pearl Harbor."
Options:
- yes
- no
**A**
no
The attack on Pearl Harbor was perpetrated by Japan.