The correct answer is 'falling-rising'.

•  Intonation refers to the pattern of rising and fall (that is, sliding in between) in the level (that is, the 'pitch') of the voice.
•  Falling and rising tones are the main two patterns of intonation.
  • Rising intonataion- We tend to use this rising intonation pattern when we’re asking questions. So the pitch of our voice tends to go up.
  • Falling intonataion- A falling intonation or downward intonation pattern, would simply mean that the pitch of the voice drops down; this downward intonation tends to be used for exclamation, statements and commands and at the end of our sentences.
• ​Fall-rise intonation describes how the voice falls and then rises. We use fall-rise intonation at the end of statements when we want to say that we are not sure, or when we may have more to add
• ​Here, In 'He has passed with distinction in English, however ...'  initially pitch is falling to English and further the speaker wants to add more in the statement 
   

​​​​Hence, we can conclude that the appropriate intonation for the sentence- He has passed with distinction in English, however, is falling-rising

• Intonation is a feature of pronunciation, and it is common in all languages.  

• Other features of pronunciation include stress, rhythm, connected speech, and accent. 
• ​The patterns of variation of the pitch of the voice i.e. the way in which the pitch varies constitute the intonation of a language.
  • Each language has its own intonation patterns. The falling tone marked thus (\) and rising tone is marks thus(/), for example
    • We should buy a \car.
    • Should we buy a /car?