Read the following article and answer the question by choosing from the options.

I went for a " run " this evening . 2 miles of mixed brisk walking and running . At some point , I noticed my hands / fingers went tingly . My fingertips were quite red , and the rest of my fingers and my palms were really really pale . Is this most like a circulatory problem , or is it just caused by hyperventilation ?

What might the speaker do next ?
Available choices:
1). Sign up for a marathon .;
2). Keep training to get better at running .;
3). Go to therapy to stop hyperventilating .;
4). Talk to a doctor about their circulatory problem .;...A:
4).