题目选项分析

Radon-210 is more radioactive than Technetium-99. Since Promethium-61 is more radioactive than Protactinium-234, it follows that Radon-210 is more radioactive than Protactinium-234.

Any of the following, if introduced into the argument as an additional premise, makes the argument above logically correct EXCEPT:

【选项】Promethium-61 and Radon-210 have equal levels of radioactivity.