आंवला मुरब्बा तैयार करने में मुख्य रूप से निम्नलिखित में से कौन सी खाद्य संरक्षण तकनीक अपनाई जाती है?

Which of the following preservation methods naturally utilizes beneficial microorganisms to biologically convert sugars into protective acids?

Which of the following preservation methods specifically utilizes salt, oil, or vinegar to create conditions that are unsuitable for microbial growth?