What is the most likely diagnosis for an elderly patient presenting with symptoms of fever, shortness of breath, cough (possibly productive), chest pain, dyspnea, and crackles on auscultation?
A) Chronic Obstructive Pulmonary Disease (COPD) exacerbation
B) Pneumonia
C) Asthma exacerbation
D) Congestive Heart Failure (CHF)