From Twitter:
Ⓐ Where’s my phone?
Ⓑ Call it.
Ⓑ Can't. Dead battery.
Ⓑ How do yo know?!
Ⓐ I tried!
Ⓑ Why would someone answer?
Ⓐ The ringer says, "Answer and win a $1,000,000!"
Ⓑ Right! No one heard!
Ⓐ Yup.
Ⓑ Where'd ya look?
Ⓐ High and lo!

High & low means:
everywhere
sky & valley

The Answer is everywhere