Which transformation acknowledges mistakes made in the past?

The correct choice highlights the idea that the mistakes made in the past are recognized and accepted. The phrase "is true that certain mistakes were" conveys a sense of validity and acknowledgment regarding those past errors. Choosing this option clearly addresses the recognition of mistakes without the additional implications that might come from other choices.

In contrast, while other options may imply that mistakes are apparent or clear, they do not specifically denote an acknowledgment of those mistakes in the same direct manner. For example, phrases like "is evident" or "is clear" can suggest understanding or recognition of mistakes but do not emphasize the aspect of acknowledging them as truths in the same way as asserting "is true." The option that states "is acknowledged that certain mistakes were" complicates the construction and shifts focus away from the direct acknowledgment to a more passive form, which can muddle the intention of the statement.