The dating became untenable once a second laboratory placed the layer three thousand years later.
当第二家实验室把该地层的年代后推三千年，原先的断代便站不住脚了。
Which choice best defines “untenable”?
D — Not defensible; indefensible.. “untenable” means Not defensible; indefensible..
Which word means “Not defensible; indefensible.”?
A — untenable. “untenable” means Not defensible; indefensible..
untenable — Not defensible; indefensible.. In Chinese: 站不住脚的；难维持的.
untenable is pronounced //ʌnˈtɛnəbl//.
The dating became untenable once a second laboratory placed the layer three thousand years later. (当第二家实验室把该地层的年代后推三千年，原先的断代便站不住脚了。)
indefensible, unsustainable, insupportable — all close in meaning to untenable (Not defensible; indefensible.).
defensible, tenable — each the opposite of untenable (Not defensible; indefensible.).
Yes. untenable is on the SAT Prep Difficult list — the higher-register words that decide the hard questions. The Digital SAT does not test vocabulary in isolation; words like this one are tested through Words in Context questions, where you choose the word that completes a passage most logically and precisely.
un(不) + tenable(可守) → 守不住。