I agree with just about everything EternalSpring said above. There are a lot of different ways to jab, and WC has many ways to deal with them. Sparring will help you figure this out for sure! My previous post was just in regards to using only taan sau against a jab. There are many more 'tools' that can be used :)
IMO, one of the best deffences against most punches is to start with a jong sau, as ES mention. If the jong works (with or without footwork as needed), then you don't need anything else. If it needs to 'change' to something else, at least you have your major gate & reference point/leverage established to work from.