Intelligence preparation of the battlefield (IPB) is led by the organization's S2/G2, and the entire staff participates to develop and maintain an understanding of the enemy, terrain, weather, & key civil considerations. During intelligence preparation of the battlefield in mission analysis and throughout the operations process, which is one of the initial IPB products used? A. Describe environmental efffects on operations B. Modified combined obstacle overlays (MCOOs), terrain effects matrices, and terrain assessments C. Critical events and decision points D. Information collection plan