Full explanation
The statement is:
"When he takes the train, Marco always arrives at work on time."
This implies:
#### If Marco takes the train, then he will arrive on time.
This is a conditional statement: Train→On Time.
1. The statement does not imply what happens if Marco does not take the train.
The reverse (converse) or negation is not necessarily true.
For instance, if Marco doesn't take the train, he could arrive late or on time---we can't deduce anything about this situation.
Analysis of the given options
#### Marco arrived late; therefore he took the train.
This suggests Late→Train, which is invalid based on the original statement.
#### Marco arrived late; therefore he did not take the train.
This aligns with the contrapositive of the statement: Train→Late.
If Marco was late, it must mean he didnʼt take the train, because taking the train guarantees being on time.
#### Marco arrived on time; therefore he missed the train.
This suggests On Time→Train, which contradicts the original statement.
If Marco is on time, it could mean he took the train, so this is invalid.
#### Marco did not take the train; therefore he arrived late.
This suggests Train→Late, which cannot be inferred from the original statement.
Not taking the train doesn't necessarily mean Marco was late.
#### Marco took his car; therefore he arrived on time.
There is no information about what happens if Marco takes his car, so we cannot deduce this.