What type of activity involves a business analyst researching products and vendors to assist a project manager?

The activity in which a business analyst researches products and vendors to assist a project manager is best classified as market research. Market research involves gathering information about market needs and preferences, which includes identifying potential vendors and understanding product offerings. This process enables the project manager to make informed decisions on suppliers, products, and strategies that align with the project's goals.

Market research provides valuable insights that help in assessing the broader context of the industry, gauging competitor capabilities, and evaluating overall market trends, which are critical for planning and executing a successful project. It ultimately supports effective decision-making by leveraging quantitative and qualitative data related to products and vendors.