Final answer:
The melting temperature (Tm) of DNA depends on the length of the strands, but not on the presence of repetitive sequences or GC content.
Step-by-step explanation:
The melting temperature (Tm) of DNA depends on various factors, including the length of the DNA strands, the presence of repetitive sequences, and the GC content. Therefore, among the given statements, statement (c) is true-
All DNA strands of equal length have equal Tm.
The melting temperature is the temperature at which the double-stranded DNA breaks apart or 'melts'. It indicates how tightly the two strands of DNA are able to bind to each other. The presence of repetitive sequences or high GC content can affect the stability of the DNA strands, but it does not determine the melting temperature.