To solve this problem, we need to understand what in-situ conservation refers to.$\newline$In-situ conservation is a method of conserving biodiversity within the natural habitat of the species.$\newline$Let's analyze each option:$\newline \bullet$Option 1: Protect and conserve the whole ecosystem.$\newline$ - In-situ conservation involves protecting entire ecosystems and natural habitats.$\newline$ - This method ensures that species continue to live in their natural environment, maintaining ecological processes.$\newline$ - Therefore, this option correctly describes in-situ conservation.$\newline \bullet$Option 2: Conserve only high-risk species.$\newline$ - This option is incorrect because in-situ conservation is not limited to high-risk species; it involves the entire ecosystem.$\newline \bullet$Option 3: Conserve only endangered species.$\newline$ - While endangered species are often a focus, in-situ conservation is broader and includes all species within an ecosystem.$\newline \bullet$Option 4: Conserve only extinct species.$\newline$ - This option is incorrect because extinct species cannot be conserved in their natural habitat.$\newline$Therefore, the correct option is Option 1: Protect and conserve the whole ecosystem.