$3.$ The authors use distance to a newspaper outlet after $1997$ as an instrument for funding reaching$$the school. They expect members of districts that are more aware of the grant will protest if the grant is not received, putting pressure on local officials to not capture as much of the grant.

Under which condition does this strategy$$enable us to estimate the causal impact of school funding $($grants received$/$grants expected$)$ on learning outcomes? Select all that is applicable

$1.$ Relevance of first stage$2.$ Relevance of second stage$3.$ Relevance of control function$4.$ Continuity in observable and nonobservable$$characteristics around the cut off point$5.$ Exclusion restriction$6.$ Sharp discontinuity