PR review: Fix typo in knowledge check explanation

Corrected a typo in the explanation for a retail challenge.

Author: AnnaMHuff

learn-pr/wwl-data-ai/define-microsoft-ai-strategy-retail/6-knowledge-check.yml

@@ -21,7 +21,7 @@ quiz:
     choices:
     - content: "Incorporating AI into offline shopping experiences."
       isCorrect: true
-      explanation: "Correct. A major challenge for AI solutions in retail is that most purchased still occur in-store."
+      explanation: "Correct. A major challenge for AI solutions in retail is that most purchases still occur in-store."
     - content: "Recruiting employees with IT skills to work in store."
       isCorrect: false
       explanation: "Incorrect. IT skills aren't a common challenge when recruiting retail employees."
@@ -49,4 +49,4 @@ quiz:
       explanation: "Incorrect. Machine learning doesn't benefit a retail organization through cloud-enabled apps."
     - content: "By helping optimize stock management through predictive analytics."
       isCorrect: true
-      explanation: "Correct. Anticipating inventory and supply chain management  is helpful to anticipate inventory and sales needs."
+      explanation: "Correct. Anticipating inventory and supply chain management  is helpful to anticipate inventory and sales needs."