Select the meaning of the underlined word in the sentence.
The effects of the treatment were ephemeral, and the patient had to be hospitalized two days after.

The meaning of the underlined word ephemeral in the sentence is "lasting only for a short period of time".

The sentence states that the effects of the treatment were ephemeral, meaning that they did not last long. The patient had to be hospitalized two days after the treatment, which means that the treatment was not effective in the long term.

The other options are not supported by the sentence. The sentence does not state that the effects of the treatment were more than what was needed, obvious, or unable to work or be together.