In the context of the input sentence, determine the relationship between 'MTN Nigeria' and 'MTN Group'.
Options: parent organization, director/manager, business division, position held

MTN Nigeria subscriber base increases but revenues drop MTN Group CEO , By MTHULISI SIBANDA JOHANNESBURG, (CAJ News ) – THE MTN Group has announced a decline in revenues at its Nigerian entity during the first half of the year.
parent organization