The best introduction to establish and introduce the claim about the need for cursive instruction in the classroom would be:
B.
Explanation: This paragraph effectively acknowledges the prevalence of technology in communication while asserting that the benefits of learning cursive should not be overlooked. It aligns well with the rest of the letter's argument, which emphasizes both the practical uses of cursive and the cognitive benefits associated with learning it. The introduction sets the stage for a discussion about the importance of cursive writing, making it a strong choice for the letter's opening.