Secret of the Old Clock starts off with a lot of conversations, doesn't it? I mean, you are forced to talk to Jane, who tells you to talk to Emily, at which point you're forced to talk to Jane again, then forced to talk to Emily again.
The second Jane conversation is about a minute long, and there are only two places where Nancy can choose which dialogue option to pick. First, Nancy can ask what caused the explosion, or if insurance will cover it. If you ask about the explosion, Jane explains that a burner was left on. If you ask about insurance, she says she asked that the fire chief, and he thinks there could be a problem. Nancy asks what the problem is, and Jane explains that a burner was left on. So either way, Jane talks about the burner being on.
It's about 5.6 seconds faster to ask what caused the explosion, because that way, Jane goes straight to the burner conversation, without detouring into insurance.
Next, Nancy can ask who was in the kitchen this morning, or where Emily went. Jane's response is exactly the same, no matter which option you pick. It's about .2 seconds faster to ask who was in the kitchen.
At this point, the conversation is interrupted by a phone call, and Jane leaves. Nancy hears Emily upstairs and goes to her.