Final answer:
Statement (c) is incorrect; it should state that RNA has one more oxygen atom than DNA, not the other way around. DNA stays in the nucleus, has ATGC bases, and is double stranded, while RNA can exit the nucleus, has AUGC bases, and is single stranded.
Step-by-step explanation:
The difference between DNA and mRNA that is not true is statement (c): "DNA has one more oxygen than RNA." In fact, RNA contains an additional oxygen atom compared to DNA due to the presence of ribose sugar in RNA instead of deoxyribose in DNA. Correcting the statement, it should actually be that RNA has one more oxygen atom than DNA. The other provided differences are accurate: DNA must remain in the nucleus while RNA can move within the cell (a); DNA contains adenine (A), thymine (T), guanine (G), and cytosine (C), while RNA replaces thymine with uracil (U), so it has adenine (A), uracil (U), guanine (G), and cytosine (C) (b); and DNA is double stranded while RNA is single stranded (d).