Answer :

To determine which blood alcohol content (BAC) level qualifies someone as legally driving under the influence (DUI) in the State of Michigan, we need to know the legal limit that is set by the law.

1. First, we review the blood alcohol percentages given:
- 0.05%
- 0.10%
- 0.08%
- 0.20%

2. The legal BAC limit for a DUI offense in Michigan is specified as 0.08%.

3. Comparing each of the BAC levels provided with the legal limit:
- 0.05% is below 0.08%, so it does not meet the limit.
- 0.10% is above 0.08%, so it meets and exceeds the limit.
- 0.08% is exactly the limit, so it meets the threshold for DUI.
- 0.20% is well above 0.08%, so it clearly exceeds the limit.

4. Based on this comparison, the BAC level that is considered legally DUI in Michigan is 0.08%.

Therefore, you are legally DUI in the State of Michigan if your blood alcohol content is 0.08% or higher.