Solution:
Given:
To get the number that is the greatest, we convert the numbers in scientific notation to ordinary numbers and then compare.
[tex]\begin{gathered} 2.3\times10^4=2.3\times10000=23,000 \\ 8.6\times10^3=8.6\times1000=8,600 \\ 1.2\times10^4=1.2\times10000=12,000 \\ 3,600=3,600 \\ \\ \text{Arranging in descending order (highest to the lowest),} \\ 23,000>12,000>8,600>3,600 \\ \\ \text{Hence, 23,000 is the greatest.} \\ 23,000=2.3\times10^4 \end{gathered}[/tex]
Therefore, the greatest among the numbers is;
[tex]2.3\times10^4[/tex]
Hence, OPTION A is the correct answer.
