FA2019, pg. 666:
Based on the findings of decreased breath sounds, dull percussion, and decreased tactile fremitus, pleural effusion is your answer.
This was more of a rule-out question than a remember-the-arrows-on-a-page-in-FA question for me!
Breath sounds are decreased, so you can rule out asthmatic bronchitis (wheezing) and pulmonary embolism (normal breath sounds, but tachypneic). Bronchiectasis can have a number of findings--crackles, rhonchi, wheezing, mid-inspiratory squeaks, etc.
Emphysema (loss of alveolar septal tissue) and pneumothorax have increased air in the lungs, therefore, they will be hyperresonant on percussion, so rule those out too.
Tactile fremitus decreases with most everything, but consolidation--low frequency sounds travel well in dense material (lobar pneumonia), but travel poorly through liquid (pleural effusion). Therefore, based on decreased fremitus, rule out pneumonia.
So...you're left with pleural effusion as your answer!