AXELOS, ITIL® 4: Digital and IT Strategy. TSO (The Stationery Office), 2020.
Section 4.3.2.3 (Sources of data): This section explicitly states, "The most valuable insights are often generated by combining and correlating data from different sources." It lists various sources, including operational data (like usage and support data), customer feedback, and market data (which includes environmental factors). This directly supports the comprehensive approach in option A and contradicts the limiting approaches in B, C, and D.
Section 3.3.2 (Knowing your customers): This section emphasizes the need for a deep understanding of customer behavior, context, and motivations to deliver value. Correlating diverse data sets as described in option A is a primary method for achieving this deep understanding.