Select the most appropriate option that can substitute the underlined word in the given sentence.
A newer, more effective computer system was installed in place of the obsolete one.

The correct answer is outdated.

Explanation:

The underlined word in the sentence is obsolete. Something that is "obsolete" is no longer produced, used, or relevant because it has been replaced by newer or better versions.

Let's analyze the given options:

1. modern: Relating to the present or recent times; new or up-to-date. This is the opposite in meaning to obsolete.
2. advanced: Far on or ahead in development or progress. This does not convey the meaning of being no longer useful or old.
3. current: Belonging to the present time; happening or being used now. This is also opposite to obsolete.
4. outdated: Out of date; old-fashioned or no longer useful. This is a direct synonym of obsolete.

Therefore, replacing "obsolete" with outdated maintains the exact meaning of the original sentence: "A newer, more effective computer system was installed in place of the outdated one."