When the two resistors are joined in series, their total resistance is $34\,\Omega$. When the same two resistors are joined in parallel, their total resistance is $7.4\,\Omega$. What is the resistance of one resistor?
- A$15\,\Omega$
- B$17\,\Omega$
- C$23\,\Omega$
- D$27\,\Omega$