The correct answer is B. Abraham Lincoln.
Indeed, at the time, Mexico had lost calamitously and suffered a disastrous defeat. Many congressmen wanted to annex all of Mexico into the United States. Others wanted only strategic parts of the country. Senator Abraham Lincoln introduced the Spot Resolutions which demanded that President Polk to provide the exact place where Mexican servicemen had shed American blood. This was due to the fact that Lincoln knew that President Polk lied when he stated that Mexicans had invaded the United States (they did intend to do it but did not have the time). The first American soldiers were killed in disputed Mexican territory.