If PQ RS , which of the following must be true?

Answer: B. [tex]\overline{PQ}\ and\ \overline{RS}[/tex] have the same length.
Step-by-step explanation:
We have given that [tex]\overline{PQ}\cong\overline{RS}[/tex], where [tex]\overline{PQ}\ and\ \overline{RS}[/tex] are two line segments.
We know that if two line segments are congruent or equal then their lengths are equal.
Therefore, if [tex]\overline{PQ}\cong\overline{RS}[/tex] then it shows that [tex]\overline{PQ}\ and\ \overline{RS}[/tex] have the same length.
Hence, B is the right answer.