Considering the available options, the maximum amount Krista may be eligible to claim for the Adoption Credit on her 2020 return is "$4,100."
Based on the rules and regulations made by the government, if an individual made more than one attempt to adopt one eligible U.S. child, such individual should add the amounts spent and complete only the “Child 1” line.
However, it is allowed to complete more than Child 1 line when individuals adopt or tried to adopt two or three eligible children.
This implies that Krista would have to add the expenses together, which is $1,600 + $2,500 = $4,100.
Hence, in this case, it is concluded that the correct answer is "$4,100."
Learn more about the Adoption Credit here: https://brainly.com/question/25813709