Choose the sentence that contains an adverb phrase:

সঠিক উত্তর: He spoke very softly. 

 Adverbial Phrase:
- যে phrase বাক্যে ব্যবহৃত হয় adverb এর মত কাজ করে তাকে Adverbial Phrase বলে ৷
- সাধারনত বাক্যকে কখন ( when), কোথায় ( where), কেন( why) ও কিভাবে (how) দ্বারা প্রশ্ন করলে উত্তর হিসেবে যে phrase পাওয়া যায় সেটি Advrbial phrase.

In the sentence "He spoke very softly," the phrase "very softly" modifies the verb "spoke" by describing how he spoke. This is an example of an adverb phrase.

অন্যদিকে, অন্য অপশনগুলোর মধ্যে, 
-  "The cat chased the mouse," does not contain an adverb phrase because there is no group of words modifying the verb "chased."

-  "She sang a beautiful song," contains an adjective phrase ("a beautiful song") modifying the noun "song," but there is no adverb phrase.

-  "They walked to the store," does not contain an adverb phrase because there is no group of words modifying the verb "walked."

Therefore, the correct answer is:  He spoke very softly.