Convert "It is cold, so we will stay inside" to a conditional sentence.

The chosen answer correctly transforms the original sentence into a conditional sentence using the first conditional form. In this construction, "If it is cold, we will stay inside," the condition is presented in a straightforward manner—if the condition of it being cold holds true at the time the decision is being made, the result is that we will choose to stay inside.

This is appropriate because the original statement suggests a present and future context, indicating that staying inside is a direct consequence of the weather being cold right now. The use of "is" in the conditional maintains this current relevance.

The other options do not fit the context correctly. One option refers to a hypothetical situation that is not relevant to the current situation, while another uses a different tense that implies a different timeframe or scenario. Therefore, the transformation in the selected answer effectively encapsulates the conditional nature of the original statement while staying true to its meaning.