Recall what the Balmer series is

The Balmer series in the hydrogen spectrum corresponds to electronic transitions in which the electron falls to the level: $n = 2$ from higher levels: $n = 3, 4, 5, \dots$

Region of the spectrum for hydrogen series

The main hydrogen spectral series are:

• Lyman series: transitions to $n=1$ $\rightarrow$ Ultraviolet
• Balmer series: transitions to $n=2$ $\rightarrow$ Visible
• Paschen series: transitions to $n=3$ $\rightarrow$ Infrared
• Brackett series: transitions to $n=4$ $\rightarrow$ Infrared

Evaluate the options

• A: Microwave $\rightarrow$ Incorrect
• B: Ultraviolet $\rightarrow$ Incorrect (this is Lyman series)
• C: Visible $\rightarrow$ Correct
• D: Infrared $\rightarrow$ Incorrect

Final answer

The Balmer series lines appear in the visible region of the electromagnetic spectrum.

$\boxed{\text{C: Visible}}$

Comparison with stored correct answer

Stored correct answer: C

My derived answer is also C, so they agree.