Explanation:

When deploying a hotfix to an ISML page in Salesforce B2C Commerce (SFCC), especially one that uses the < iscache > tag, you must consider the page caching mechanism.

If a page is cached (either fully or partially), any changes you make to the ISML file won’t take effect immediately in production unless you invalidate the cache.

🔍 Why Option A is Correct:
"It will be required to invalidate the cache for the hot fix."
✅ True
SFCC caches pages and templates aggressively in production for performance.
If the ISML page is cached using , then even after you deploy the updated template, the cached version might still be served.

You must either:
Manually invalidate the page cache via Business Manager or
Deploy with a code version change and trigger automatic cache invalidation
➡️ Failing to invalidate cache means your hotfix won’t be reflected immediately, making troubleshooting ineffective.

❌ Why the Other Options Are Incorrect:
B. "If the page has multiple tags, the highest cache duration is used" ❌ Not accurate.
Cache scope and duration are defined per tag — it doesn’t combine or inherit from others globally.
The final caching behavior depends on the outermost scope or how the template is included.

C. "TTL only affects static content, not the page cache" ❌ Misleading.
TTL (Time-To-Live) defined in does affect page cache.
It's used to determine how long a rendered template stays in the cache before expiring.
So yes, it can absolutely affect dynamic ISML behavior, which may be the root cause of the issue.

📘 Reference:
ISML < iscache > Tag Documentation
Cache Invalidation Guide