I'm doing an article section related to bootstrap 4 but, the problem is that nothing is achieved to see an item instead of the 4 that should have the carousel.
<div class="container">
<div class="col-sm-12">
<h3>ARTÍCULOS RELACIONADOS</h3>
</div>
<hr>
<div class="col-sm-12">
<div id="carouselExample" class="carousel slide" data-ride="carousel" data-interval="9000">
<div class="carousel-inner row mx-auto" role="listbox">
<div class="carousel-item col-sm-3 active">
<img class="img-fluid mx-auto d-block" src="http://www.solerpalau.mx/multimedia/imagenes/productos/b0213267bdda4803590a1651776e24ea672736e1.jpg" alt="slide 3">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="http://www.solerpalau.mx/multimedia/imagenes/productos/3359c2cd6f609c23549adf36207725bc9ebf0418.jpg" alt="slide 4">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="http://www.solerpalau.mx/multimedia/imagenes/productos/d984e5d39ffbd8453676a837e5d0480fe48e5ede.jpg" alt="Card image cap" alt="slide 5">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="//placehold.it/600x400/000/fff?text=1" alt="slide 1">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="//placehold.it/600x400?text=2" alt="slide 2">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="http://www.solerpalau.mx/multimedia/imagenes/productos/b0213267bdda4803590a1651776e24ea672736e1.jpg" alt="Card image cap">
<div class="card-body">
<h6 class="card-title">Extractores para Pared y Cristal</h6>
</div>
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="//placehold.it/600x400?text=6" alt="slide 6">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="//placehold.it/600x400?text=7" alt="slide 7">
</div>
<div class="carousel-item col-sm-3">
<img class="img-fluid mx-auto d-block" src="//placehold.it/600x400?text=8" alt="slide 7">
</div>
</div>
<a class="carousel-control-prev" href="#carouselExample" role="button" data-slide="prev">
<i class="fa fa-chevron-left fa-lg text-muted"></i>
<span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next text-faded" href="#carouselExample" role="button" data-slide="next">
<i class="fa fa-chevron-right fa-lg text-muted"></i>
<span class="sr-only">Next</span>
</a>
</div>