Write a question about the following article.

Add the onions and some salt sweat until sweet and translucent . Add the peas and defrost in the skillet with the onions . When the peas are fully warmed , turn off the heat of the skillet . Add the yogurt , tarragon and pistachios .

Question:
Why are the onions added first ?
Choices:
(1). The onions need to be cooked longer ..
(2). The onions have too much salt.
(3). None of the above choices ..
(4). The onions are added after the yogurt ..