Answer:
Internal preview.
Step-by-step explanation:
Internal previews are defined as the type of connectives that occur immediately after the transition and are primarily employed to direct or foreshadow the readers/audience about the upcoming main point that is going to be covered next. The speaker usually lists the sub-points which together make up the main point.
The given statement would be characterized as the 'internal preview' kind of connective if it occurred in a speech as it is a brief statement that forecasts the upcoming point of the speech('the two types of solving the problem of groundwater contamination'). It helps in preparing the audience for the next idea and also in maintaining order in the speech that comprehends better understanding.