Explanation

ACE2 (Angiotensin-Converting Enzyme 2) is a membrane-bound functional enzyme expressed across mucosal tissues including the lungs, heart, kidneys, and gastrointestinal tract.

– During the COVID-19 pandemic, ACE2 gained worldwide medical prominence as the functional cellular receptor utilized by the SARS-CoV-2 coronavirus to gain entry into human host cells.
– The spike glycoprotein on the envelope of the virion binds directly to the outer enzymatic domain of ACE2, enabling fusion and cellular infection.

Hence, the term ACE2 is discussed in the context of the spread of viral diseases — Option D.